Drilling machine



Feb. 2, 1932. w. E. CARR DRILLING MACHINE 2 Sheets-Sheet l Filed March 8, 1930 WM 75H tL-A @H Inventor By m Atlorney W. E. CARR Feb. 2, 1932.

DRILLING MACHINE Filed March 8, 1930 2 Sheets-Sheet 2 WM 75H Tf/.1 /P/P Inventor MM By A ltor ne y Patented Feb, 2, 1932 UNYTED- gsrra'rss PATENT OFFICE WALTER E. CARR, OFSPOKANE, WASHINGTON DRILLING MACHINE Application led March .8,

My present-'invention relates to improvements in drilling machines of-the pneumatically operated,` reciprocating type usually employed in mining work and tunnel operai'tions, and the vinvention relates particularly left halidand thereby controls the pneumatically operated, reciprocablc motor and its drill. The right hand, of the operator is usually employed to turn a crank, thereby rotating a feed screw bar (which bar is stationary) for advancing the drilling machine. lDue to the air pulsations in the pneumatically operated reciprocating motor, the drill is reciprocated, and; because of the these vibrations, lnown as the kick of the. drilling machine, the latter is bodily reciprocated, .but slightly, with relation to its supporting frame.

Y In carrying out myy invention I utilize the power' in the flri'ckl for automatically advancing or feeding the drilling machine with Vrelation to its supporting frameand thereby dispense with the usual manually operated feed for the drilling machine. The continuous vibrations or kiek of the usual, stand ard, manually-fed drilling machine, passing through both hands and arms of the operator, subjects him to an undersirable nervous strain, which strain is materially reduced by the use of my invention, and the automatic feed of the drilling machine in lieu of the manual feed releases one hand of the operator for other uses. f

` tained.V In the accompanying drawings I rhave shown a welllrnown type of drilling machine equipped with ythe automatic feed of 1930. Serial No. 434,274.`

my invention, and the parts are combined and arranged therein in accord with one mod-e that I have so far devised for the practicalapplication of the principles of my invention.

Figure l is a View in side elevation showing a drilling machine and its stationary frame, part ofthe latter being omitted for convenience ofillustration. i Y Y Figure 2 is an enlarged detail exterior view, as seen from the rear of Figure l, showing part of the stationary feed, rack-bar with the operating pawl in reverse position fromgthat of Figure l, and showing alsoa bralredevice for the drill machine'.

Figure 3 is a sectional detail View atl line 3 3 of Figure 2. A i

Figure 4 is a longitudinal sectional View at line 4-4 of'Figure 3 with the operating pawl in position of Figure 2 for feeding or advancing the drilling machine.f

Figure 5 is a detail sectional view at line 5-5 of Figure 2 showing particularly the brake. device for the drilling machine.

In order that the general arrangement and relation of parts may readily be understood I have shown in Figure 1 a standard type of drilling machine for use in mines and in'tunnel work, and employing the usual reciprocating drill l. The drilling machine includes the cylinder 2 with the front head 3 and rear head 4f, and. the hose for compressed air or other motive fluid is introduced to the cylinder at the port 5. By dotted lines a reciprocati ng valve 6 is illustra ted for controlling the admission of air to the piston 7 that reciprocates inusual manner with the drill or bit 1.

The throttle lever 8 is usually grasped in the left hand of the operator for controlling admission of the compressed air .or other inotive fluid to thc interior of the cylinder. The parts thus described I shall hereinafter refer to as the drill with its bit l, and it will-be understood that the bit is reciprocated for delivering hammer blows as it is turned for drilling the hole.

Under the air pulsations for reciprocating the bit, the drill as a whole is also, longitudinally reciprocated with relation to the supporting frame or tubular housing 9 that is TY known as the feed shell. This shell is stationary, and it is provided with a boss 10 that is properly coupled or connected with a swivel joint, not shown, and the joint and shell are supported upon an upright column, not shown.

I utilizethe longitudinal vibration or reciprocation of the drill, (known as a kick) with relation to the shell 9 for feeding or advancing'the drill with relation to the shell, and the latter forms the guiding support-for f the drill.

hollow feed block 16 which is fashioned with Vdiverging,perforated lugs 17, and a pair of tie bolts 18Lconnect these lugsiwith a cylinder bushing v19 that has perforated ears 2O for the bolts. Nutsy 21 at the ends of the bolts are 1 used to securethe tie'bolts, and in this 'manner the feed block is .rigidly mounted on and at the rear of the drill.

The hollow block has a bushing22 through which the rack'bar passes, and in Figure 1 a sleeve 23, forming part of the cylinder, surrounds the bushing, and the parts are locked together with a lock, nut 24 threaded on the end of the bushing 22.

Thel lower end of the block, the bushing, sleeve and nut are designed to travel forward in the shell 9 as the drill is fed or advanced to itswork. j Y .Y

For co-action with the stationary rack bar I mount kan' operating pawl in the hollow block, and this pawl is reversible to permit forward or rearwardtravel of the drill with relationl to the shell. The reversible pawl -has two arms 25 and 26 and a head 27 and it is enclosed within a recess 28 of the hollow block.- The head is mounted upon and fixed by a clutch30 to a rack pin 29 that may os- `cillate or rather be osci'llated on the bearing` .or journal 30'of the pin, a nut 31 being used to hold the pin in its bearings. A replaceable sleevey 41 may be used to support the pin 29 -atiits en d adjacent the nut 31. I

'llThe piawl is manually controlled andin connection with it I use a. snap spring 33 that-holds one orthe other of the pawl-arms 25,26 injcontact with the rack bar. The lever farm 32 rigid with the pin 29 is used to swing or rock the pawl, and the spring is coiled about a pin 34 that is secured in a lug 35 lof the lever arm. The spring pin has a bearing head 36 in a socket in the feed block, l which as seen in Figure 4 is out of line with detent or arin26 engages the rack bar, thus permitting the spring to hold the pawl in released position. In Figure 4, as the drill ,operatesunder pulsations of air, the drill is longitudinally reciprocated, or jumps thus providing mensual-kick A rearward movement, under the kick is preventedy by fthe co-action of the detent 25 and the rack bar, but upon the forward jump, following the kick-back, the drill advances the distance of a tooth of therack bar land the detent therefore engages the nextjforward tooth of the raclfbar. The continuous operation of `the drill for reciprocatingthe bit ultimately and automatically feeds theidrill to the limit of its forward position, after which the pawl is reversed andthe drill isretracted in usual manner for ,another advance movement or feed.. 2 Y

It will be understood that the drill may be used in horizontal position, or disposed at an anglerto .thehorizontah and in the latter instanceit is desirable to control, as by a brake, the `relative movement or sliding of the drill with relation t-o theV frame or housing or feed shell 9', which shell is of course also disposed at an angle and parallel with the drill. f Y

For this purposeI employ a 'frictionbrake device between the drill and its feed bar, or rack bar, the brake being located in the hollow feed block and coz-acting therewith. The brake includesa split, expanding, shoe or nut 37 located in a recess 38 in the feed block at one side of the rack bar or feed bar 11V and adapted to contactwith the rack bar and withthe wall of the recess'in the block. An expanding, tapered screw 39- is threaded at a suitable angle in the expanding block or nut, and they screw is`turned by use of the handle or head 40. The screwimayvbe turned as desired to incr-ease or diminish the friction between the brake shoe and theadjoining friction faces, thus retarding the movement ofthe drill, or freeing the drill, but of course thefriction is not sufficient to stop the bodily reciprocating-movement of the drill under the air pulsations or impulses in the pneumatic motor ofthe drill.

Having thus fully described ,my invention,

what I claim as new anddesire tosecure by Letters PatentjS:

ki. in ,a drilling machistas descfibed, the

combination withk a feed shell and its sta- ;tionary rack bar, of a relatively movable enclosing part of the bar, a two-armed pawl pivoted in the block for co-action with the bar, means for shifting the pawl, me-ans for releasing the pawl from the bar, an expansible brake shoe between the feed block and the rack bar, and means for expanding the shoe.

2. In a drilling machine as described, the combination with a feed shell and its stal@ tionary rack bar, of a relatively movable drill, a hollow feed block mounted on the drill, a reversible pawl pivoted in the block for co-action with the rack bar, a snap spring for retaining the pawl in shifted position, 1g an expanding brake shoe in the block for friction engagement with the rack bar, and means for expanding the shoe for the purpose described.

3. In a motive Huid operated reciprocating 39 drill receiving impulses under pressure, the combination with a stationary guide for the drill and a feed block on the drill, of coacting means on the feed block and guide actuated under the kick of the drill for feeding the drill, an eXpansible friction member between the guide and the feed block for retarding the movement of the kick, and means for expanding said member.

In testimony whereof I ax my signature. 30 WALTER E. CARR. 

